1. Technical Field
The present invention relates in general to structures and their construction and in particular to structures having an intrusion barrier to preclude entry of rodents and other pests within the structure. Still more particularly, the present invention relates to structures having integral intrusion barriers and a method for incorporating integral intrusion barriers into the construction of structures.
2. Description of the Related Art
The intrusion of rodents and similar pests into dwellings and other structures is a long standing problem that often results in food spoilage, destruction of property, and unsanitary and unhealthy conditions. In the past, most solutions to the problem of rodent intrusion have focused on trapping or poisoning the rodents within a structure, which besides being less than completely effective, may entail the disagreeable jobs of locating and disposing of the rodent (or carcass) when effective. Such lethal measures may also cause a rodent to die within inaccessible spaces of the floor, walls, or ceiling of a structure.
Of greater concern is that rodents have historically (and recently) been linked to outbreaks of aggressive and often fatal infectious diseases, for which rodents may serve as hosts without suffering any ill effects. For example, in the last ten years, there have been numerous publicized outbreaks of two acute diseases for which hantaviruses have been implicated as the etiologic agent: hemorrhagic fever with renal syndrome and hantavirus pulmonary syndrome (HPS). The hantavirus strains that cause both diseases are carried by rodents and are believed to be transmitted to humans through the respiration of the excreta of infected rodents. The predominant host for hantaviruses in the southwestern United States is the deer mouse (Peromyscus maniculatus), which has a pernicious propensity to enter human dwellings in search of food or shelter. As noted above, hantaviruses are particularly aggressive; for example, once a human is infected with HPS, severe respiratory difficulty is probable within as little as 12 hours, and death may occur in as little as 24 to 36 hours. The incidence of mortality due to HPS is currently 40%. Against such significant threats to human health, prior methods of addressing rodent intrusion after intrusion has occurred are unacceptable.
It is evident that a preferred alternative to controlling rodents is to prevent rodent intrusion entirely. One way in which the likelihood of rodent intrusion can be reduced is to select exterior materials (e.g., masonry veneer) that are resistant to rodent intrusion. Although such precautions may avail against rodent intrusion, it is often not economically or otherwise feasible for a structure to be constructed from such materials. For example, if portability and low expense are requirements for a particular application, a structure cannot feasibly be constructed for that application utilizing masonry veneer. This is particularly true with respect to manufactured housing (e.g., mobile homes), where the use of economical materials and construction techniques are required in order to ensure that the homes are affordable and portable. Thus, due to the requirements of portability and affordable pricing, manufactured housing and other prefabricated buildings are particularly susceptible to rodent intrusion. Other structures, however, are also susceptible to rodent intrusion. For example, structures having floors of pier-and-beam construction are vulnerable to rodent intrusion from below, and structures having composite or wood shingle roofs are vulnerable to rodent intrusion from above.
Therefore, there is a need for an effective system for preventing rodent intrusion into structures that is economical and applicable to both portable and other structures.